Adding lenalidomide (Revlimid) to the chemotherapy regimen led to greater toxicity and worse survival in patients with untreated castration-resistant prostate cancer (CRPC), results of a large international trial showed. Men randomized to a regimen of lenalidomide, docetaxel, and prednisone, had a 53% increased mortality hazard, a 32% greater hazard for progression, and significantly higher rates of neutropenia, febrile neutropenia, and multiple non-hematologic adverse events.